Most existing wireless systems use static allocation of radio spectrum. Each system operates in a predefined fixed frequency band. Since the allocated spectrum is not used at all locations and at all time instants, this static allocation leads to creation of spectrum holes, which implies inefficient utilization of the available radio spectrum. A much better spectrum utilization can be achieved with systems using dynamic spectrum allocation. These systems must have a completely new feature: spectrum sensing capability. Spectrum sensing can be defined as RF signal analysis whose goal is to determine if the observed frequency band is occupied and possibly identify or characterize the signals present.
It is therefore desirable to have systems and methods that analyze RF signals.